NIAID scientists and their colleagues have expanded the focus of collaborative studies at the International Center for Excellence in Research (ICER) in Mali to include several diseases recently identified in the West African nation: tick-borne relapsing fever (TBRF), Lassa fever and Crimean-Congo hemorrhagic fever (CCHF).
The NIAID Division of Intramural Research has conducted studies in Mali since 1990. The ICER, established by NIAID in 2002, is part of the medical school campus at the University of Sciences, Techniques and Technologies of Bamako in Mali’s capital. Its original goal was to serve as a focal point for malaria research, engaging Malian and NIAID scientists in studies involving mosquitoes, malaria drug resistance and candidate malaria vaccines. Subsequent cooperation included research on neglected tropical diseases such as filariasis and leishmaniasis as well as studies of individuals co-infected with HIV and tuberculosis.
The scope of the collaboration expanded again in 2008 and 2010 when scientists from NIAID’s Rocky Mountain Laboratories (RML) identified the TBRF bacterium and Lassa fever virus in rodents obtained from Mali villages. More recently, the same visiting scientists identified CCHF virus in Malian ticks.
TBRF is rarely fatal and can be treated with antibiotics. However, there is no vaccine or widely accepted treatment for Lassa or CCHF. Each year, an estimated 100,000 to 300,000 people in West Africa are infected with Lassa, leading to approximately 5,000 deaths. Case reports for CCHF are not available, though the mortality rate ranges between 10 and 40 percent, according to the World Health Organization. CCHF occurs in Africa, the Balkans, the Middle East and Asia.
|Weekly cattle markets in Mali provide NIAID researchers with access to ticks that serve as vectors for diseases such as Crimean-Congo hemorrhagic fever virus.
NIAID’s CCHF project in Mali also has expanded research partnerships to include veterinarians and ranchers. Together they hope to more efficiently identify regions where the disease may be widespread in cattle.
CCHF is typically transmitted to humans either by a tick bite or through contact with infected tissue or fluids from cattle. The researchers already have identified some regions of high incidence for TBRF and Lassa and are hoping soon to receive permission to obtain human blood samples to assess infection prevalence. Through this collaboration, NIAID scientists also are sharing expertise and resources with Malian clinicians so that they can detect disease-causing organisms in their patients.
The NIAID projects also have helped U.S. and Malian scientists collect nearly 4,000 ticks in Mali. These ticks, collected at cattle markets, are being analyzed at RML for multiple infectious agents. RML also plans to use the ticks to establish a colony for use in future studies of CCHF transmission. The group also seeks to obtain rodents from Mali to establish a Lassa fever study model.
Dr. Dave Safronetz is leading the Lassa and CCHF projects for NIAID’s Laboratory of Virology. Dr. Tom Schwan is leading the TBRF project for the Laboratory of Zoonotic Pathogens. Both say that the studies have been scientifically rewarding and highly productive.
Members of different lab organizations—bacteriologists and virologists—are studying the same specimens while also teaching Malian physicians about new infectious diseases. Because the symptoms of these diseases often mimic malaria, these researchers also are focusing on training that will allow local physicians to more accurately diagnose a range of infectious diseases so they can be treated effectively.